StALKBH10B ‐Mediated RNA m 6 A Modification Inhibits Potato Salt Tolerance by Targeting Flavonoids and ABA Signalling Pathways

N6-methyladenosine (m6A) is the most prevalent methylation modification present in mRNAs, which has been confirmed to participate in many developmental and biological processes. However, the biological function and specific regulatory mechanism of m6A modification in relation to salt tolerance of potato remain obscure. Here, we generated a transcriptome-wide m6A map using salt-resistant and salt-sensitive potato varieties under salt stress conditions to uncover patterns of m6A methylation in the potato response to salt stress. MeRIP-seq revealed that m6A is significantly enriched in the CDS region in potato, by recognising the conserved motifs including RRACH and URRUAY. Numerous differential m6A-deposited transcripts have been identified, which were significantly enriched in ABA-signalling and flavonoids biosynthesis pathway in two potato varieties after salt stress. Notably, a positive correlation was observed between the m6A enrichment and mRNA abundance based on combined analysis of MeRIP-seq and mRNA-seq. StALKBH10B was identified as an m6A demethylase for decreasing m6A modification levels, inhibiting mRNA stability and translation efficiency of ABA signal-related genes (StABF3, StAAO3, and StZEP7) and flavonoids biosynthesis genes (StPAL3, StCHS, and StFLS), and overexpression of StALKBH10B suppressed salt resistance in potato. Collectively, we uncover a novel mechanism of post-transcriptional modification involved in affecting salt stress response in potato, via StALKBH10B-mediated m6A demethylation on targeted transcripts in the ABA signalling and flavonoids biosynthesis pathway, thereby providing candidate genes for the breeding of stress-tolerant potato cultivars.